Propeller



Oct. 25, r1938,A M. D; THOMPSON PROPELLER Filed Ag. 9, 1937 15 complish the first object by means whichper- Referring t0 the drawing. l iS a Propeller Shaft, 16 mit the blades to rotate on their axes through an xedly secured vto which. by a key la. is a prol arc of substantially one hundred and eighty deseller-shaft hub having Outer end straight porgrees, or half a turn, tions 2 and an intermediate part 2a conforming The second object is attained through the t the Shape 0f a fri-Stuhl 0f a Sphere 20 agency of the particular form or contour of the In the portion 2a are tWO grOOVeS 3 and 4. one 20v Patented oct 25, 193s i ,l34,l57

UNITED STATES PATENT OFFICE raoPnLLnn Milton D. Thompson, Fairhaven, Mass. Application August e, i937, serial No. 158,049 i claims. ici. 17o-162) This invention relates to propellers, particularler with one half of the two-part casing removed, ly that type commonly known as the "feathering the blades being disposed in the ahead posiblade. In this type the blades are capable of tion;

limited rotation on their own axes. Fig. 5 is like Fig. 4 except that the propeller- 5 In my-present invention I have in view two shaft hub has been rotated, relative to the casprincipal objects;- ing, to bring the blades into astern positions;-

First: To provide means whereby that face oi' Figs. 6 and 7, are respectively, the two grooves the blade which is most eclent for propelling in the hub member developed on a plane surface purposes is always used-either for going ahead to show their exact contours;

or going astern movements of the vessel. Fig. 8 is a transverse section through the parts, lo

Second: To evolve a propeller in which the taken 0n a Central line through the blade flanges; blades themselves are utilized in the operation of Fig. 9 is a section on line 9-j9, Fig. 4, and re-arranging them' when a change in the direc- Fig. 10 iS an end View. Partly in SeetiOn. 0f One tion of movement of the ship is desired. I ac- 0f the propeller bladeS.

blade, there being anexcess of water-impacting dlalnetrleally ODDOSite the Other. Both grOOVeS surface on one side of the axial line of the blade, are Spire-lling and grOOVe 3 Somewhat irregular in making it out of balance, axially. contour. Should there be more than twoblades The preponderance of working face is on the in the Propeller aSSembly a COrreSDOnding numwater-leaving or trailing portion of the biade, ber 0f grooves would be Supplied. -25 this portion extending transversely a greater dis- In Figs. 6 and 7 the contour of these groove tance from its axial line than does the entering are shown as they would appear were their or cutting edge on the opposite side of the axle outlines transferred to a plane surface. Their line. Its action is somewhat analogous to a functions will hereinafter be explained.

weather vane, the tail of which swings the vane EnClOSing the Propeller-Shafthnb iS a tWO-Dart 30 when the wind shifts from one quarter to another. Casing 5. the DOI'tlOnS 2. 2 0f the hnb being J'Ollr- When my propeller is employed on auxiliary nailed in the bearings 6. 6, respectively, of the powered vessels these trailing portions of the casing and capable of restricted rotation therein. blades cause them to automatically come into The outside surfaces of these bearings are screw longitudinal feathering positions when the power tlrn'eaded. at l. t0 reCeiV respectively. the Cellars 35 is shut o. Immediately the propeller shaft starts 8 8 which Serve t0 rigidly Clamp the tWO Similar to revolve, these trailing portions, by impacton halves 0f the Casing together. on the water, force the blades' to turn on their 0n ODDOSite Sides 0f the assembled Casing 5 are axes a certain amoun1; the propeller hub mechcircular ilanges 9, the latter being disposed in the 4o anism cooperating to bring the blades into their circular gIOOVeS l0 in the hubs Il 0f the Propeller 40 full Working pitch positions. blades i2 and I2a, respectively. The hubs il of For a clearer understanding of the import of the blades rotate on their axes within the ciriny invention reference should be had to the decular lange. but like the prepeller-Shaft hub. the scrlption found in the following specification extent 0f their IOtatiOn iS limited.

when taken in connection with the accompanying The faces 0f the narices 9 cvnveree slightly to- 45 drawing in which like reference characters are Ward the aft end of the propeller. thllS Producing employed to identify like parts in alll the different an aftward rake t0 the blades.

views thereof. In the drawing,- On the hub i i of each blade ls a pintle or Fig. 1 is a side view of the propeller, showing gudgeon, the pintle i3 on the blade I2 extending the blades in the "go ahead positions; into the groove 3 and the pintle il on the blade 50 Fig. 2 is the same, except that the blades are Wd engaging the grOOVe 4- positioned to drive the ship astern; By observing Fig. 3 it will noted that'the Fig. 3 showsithe blades in feathering posiform or contour of the blades is unsymmetrical. tions, when the propeller shaft is idle; 'I'his makes them out of axial balance, the por- Fig. 4'shows a fragmentary view of the propeltion X extending much further from .the axial 55 line S.-S of each blade than does the cuttingedge portion C. E.

The trailing portion X on the water-leaving side of the axial line of each blade is also greatly in excess of the portion on the opposite side of the axial line when the propeller is viewed normal to, or at a right angle with, the propeller shaft I. Thus when brought to their full or working pitch positions, (as shown in Figs. 1 and 2), the path cut in the water by the revolving blades lies largely on the trailing (X) side of their respective pivotal center lines.

With the parts arranged as shown in Figs. 2 and 5, and the shaft revolving in the direction indicated by the arrow A, the ship orv boat will be propelled astern, the nut Z indicating that this is the aft end of the propeller shaft. The pintle I3 will be disposed at the rearward end of the 4groove 3 and the pintle I4 located in a corresponding part of the groove 4.

The positions, relatively, of the pintles in their respective grooves are more comprehensively shown in Figs. 6 and '7, in vwhich the periphery 2a of the propeller shaft hub is developed into a plane surface and the grooves outlined thereon.

Starting with the pintles I3 and I4 in the grooves in which they respectively operate when driving the ship astern, their positions as represented in the Figs. 6 and 7 are at I3a and I 4a, and rotation of the propeller shaft I in the di'- rection indicated by the arrow B will drive the ship in the direction just mentioned,-astern.

At this point, with the parts arranged as shown in Figs. 2 and 5, let it be assumed that a change in the direction of movement of the ship to ahead is desired, to accomplish which it is necessary to re-position the blades so that they will appear as illustrated in Fig. 1.

Now at the start of the change in direction of rotation of the propeller shaft from what is designated as astern, as indicated by arrow A, to ahead" which is indicated by the arrow B, the blades lag, or do not immediately and simultaneously respond to the rotary movement of the shaft, and there develops a rotary movement, relatively, between the propeller shaft hub 2-2a and the casing 5. 'This brings the pintles I3 and I4 from positions I3a and Ila. to positions I3b and Mb, respectively.

Thus far there will be no appreciable axial rotation of the blade I2a, but, 'due to the sli'ght lead or advance in this portion of the groove 3,

represented by D, the pintle I3 will act to giver the blade I2 a comparatively small axial rotation.

Now from this. point onward (from positions I3b and IIb) the blades have two agencies acting to turn them on'their axes, the pintles and grooves being one, and the resistance of the water against which the trailing portions of the blades impact, being the other.

After the pintles I3 and I4 have advanced in the grooves 3 and 4, respectively, to positions I 3b and Mb, the pintle I3 engages anabrupt projection 3a extending into the groove 3. This gives the blade I2 a sudden and impulsive axial movement, disaligning temporarily the portions X of the two blades, the pintle I3 moving to position I3c and the pintle Il at the same time advancing in an easy stage to position Mc, at which positions the two blades are v1n substantially similar pitch angles with the shaft, and in approximately transverse feathering positions.

As the propeller shaft continues to revolve, the resistance of the water on the blades causes still further movement, relatively, between the hub 2-2a and casing 5, and this movement advances the pintles into positions I3d and IlId, the water at this time assisting, infact acting as the primary agent to continue the axial movement of the blades until they come into positions I3e and Ile, at which places they are disposed at the opposite ends of the grooves 3 and l in full workirtig pitch positions for ahead movement of the s p.

When changing the positions of the blades, from that in which they drive the ship astern to that in which they propel it ahead, the ilrst part of this operation is accomplished mechanically, or through the agency of the pintles and grooves.

The reason for this requirement will be apparent when it is borne in mind that during this period (the first portion of the axial turning movement of the blades) the water impacts strongly against the trailing portions X, thereby hindering rather than assisting, by water means, the rotation of the blades on their axes, while the propeller as a whole is revolving.

This condition exists untilV the blades have axially rotated slightly beyond their transverse feathering positions, at which time the water does assist, in fact almost exclusively provides the means for their axial rotation.

Furthermore, it is obvious that it takes less power, and the parts are subjected to a less amount of strain and wear if, during this mechanically actuated portion of the full axial rotation of the blades, they are acted upon separately. And for this reason and to attain the objects inferred from the foregoing statement, one of the blades is made to rotate on its axis in advance of the other, through the instrumentality of the pintle I3, which is integral with the advancing blade I2, riding the projection 3a, which operation suddenly brings the trailing portion X of the blade I2 out of the circular path of the trailing portion X of blade I2a, and into substantially transverse feathering position where resistance Ato rotation by and with the propeller shaft is greatly lessened.

After the pintle I3 passes the projection 3a and enters the portion of the groove 3 which is' disposed normal tothe axis of the propeller shaft, and until it arrived at the position I3c, there is no axial rotation of the blade I2. In other words, after the pintle enters this lead-less portion of the groove 3 the blade axis and is temporarily held in substantially transverse feathering position, in which position there is very little power expended in revolving the propeller insofar as blade I2 is concerned.

Now blade I2a must be brought into the same position, relatively, as that in which blade I2 is at this time disposed,-that is, transverse feathering position.

After the blade I2 ceases to rotate on its axis, the pintle I4, moving along the slot l, causes the blade I2a to'gradually rotate on its axis until upon reaching the location Ilc it is disposed in transverse feathering position, comparable to that of blade I2.

The twoy blades, I2 and ing to the positions I3c and llc, respectively, are brought into their full pitch positions mainly by their impaction on the water, as the propeller as a whole revolves.

A lug 'I5 on each blade engages a stop member I6 on the casing preventing further axial movement of the blade. A corresponding stop member I2a, shortly/after coml I2 ceases to rotate on its is provided on the opposite side of the casing to limit the axial movements of the blades opposite direction.

in the Fig. 10 shows'one of the blades, end on. The

screw propeller is contemplated.,

.The are Y, shown in Figs. 6, 7 and l0, measures the angle through which the blades swing on their axes in moving from positions l3nt and. Md

vto positions 13e and Me, respectively.

. The casing 5 may be lled with grease for lubricating the working parts therein, the screw l1 being removed to gain access to its interior.

I have hereinbefore described in detail the steps required to be taken to change the positions of the blades from that in which they propel the ship astern to that in which the ship is made to move ahead. The reverse operation, or that in which the blades are positioned in'v the ahead propelling positions and are to be changed to the astern ship-driving duty, is conducted and accomplished in a quite similar manner, except for a certain difference in the order or sequence in which the two forces, mechanical and water-impact, are applied to the blades to rotate Ithem on their axes.

With conditions such as are presented in Fig. l, in which is shown a right-hand propeller, rotating as indicated by the arrow B, calculated to drive the ship ahead, and it is desired to reposition the blades to drive the ship astern, the first move is to change the direction of rotation of theshaft, so that it will revolve in the direction of arrowl A. Immediately upon reversing the direction of rotation of the shaft the outwardly extending trailing portions X of the blades impact the water and cause the blades to turn on their axes, and this turning movements is continued until the blades arrive at substantially transverse feathering positions and the water no longer has any axially turning effect on the blades. During this portion of their axial-rotating movement thel blades have turned in the direction of the arrow M.

But as the shaft and blades continue to revolve together, the resistance of the Water on the blades is sufficient to cause a movement, relatively, between the casing and the propeller shaft hub,

.resulting in the pintles and grooves functioning to complete the axial turning movement of the blades and bring them to their full pitch positions to drive the ship astern.

So it is evident that the first part of the axial turning movement of the blades is, in this oper' ation, accomplished by water impaction, and the last portion by mechanical me Now with respect to the change from "astern to ahead movement of the vessel, and the sequence of operations necessary to re-arrange the blades to accomplish this object, We will describe it by starting with the blades arranged as shown in Fig. 2, with the shaft rotating in the direction indicated by the arrow A. The vessel is nowmoving astern. But it is desiredto arrange the blades so that the vessel will-be propelled ahead. As was the case inthe previous change of positions of the blades, the shaft I is first made to revolve in the opposite direction,-

that is, according to arrow B. But in this instance the blades are `set so that advantage cannot be taken of the water to start them rotating on their axes, so the first Vportion of the turning movement of the blades on their axes must be accomplished through the instrumentality of the pintles and grooves which, by the over-riding action of the casing on the propeller shaft hub, develops a movement, relatively, between these two elements which force the blades into and slightly beyond their transverse feathering positions, at which time the pressure of the water acts on the trailing portions of the blades and quickly brings them into their full pitch positions, for driving the vessel ahead. The blade inthis operation turns as indicated by the arrow N, Fig. 5.

In contrast Iwith the first operation described wherein the blades were changed from the ahead to the astern positions, this latter operation where the blades moved from the astern to the ahead arrangement thereof, started with mechanical actuation of the blades and finished by the impact of the blades on the water.

It will be noted that in whichever direction the blades are to be moved for re-positioning, "ahead to astern ror vice versa, a greater proportion of the axial movement is brought about through the direct action of the water on the trailing portions of the blades.

It is further to be observed that, Whether driving the ship ahead or astern, the most eicient and identical Working face of the bladev does the driving.

My propeller has proven very practical use, particularly with respect to its efficiency when the vessel or boat is being driven astern.

In auxiliary yacht service the longitudinal feathering feature is of great advantage, as the blades automatically come into positions as shown in Fig. 3 when the shaft stops revolving. Another feature resides in the construction of the blades, which are similar, and one spare would t in place of either of the regular blades should one of them become injured.

What I claim is:

1. A propeller mechanism vcomprising in combination with a propeller shaft, a propeller-shaft hub xedly secured to grooves therein extending satisfactory in partially therearound, one of said grooves having,

for a predetermined distance from one end, a slight lead, a two-part casing enclosing said propeller-shaft hub, two bearings on opposite ends, respectively, of said casing in which said propellershaft hub is journalled rotation therein, two circular flanges disposed on opposite sides, respectively, of said casing, a propeller blade, having a circumferential groove in its hub portion, rotatively mounted in each of said anges, and a pintle on the hub of each of the propeller blades, the two pintles adapted to engage, respectively, the two grooves in said propellerfshaft hub.

2. A propeller comprising in combination with a propeller shaft, a propeller-shaft hub/element xed on said shaft, the central portion, lengthwise of said hub being frusto-spherical in shape and having a. plurality of irregularly contoured grooves in, and advancing along the periphery thereof, a casing, formedof two similar half-portions, having a bearing at each end in which the two end portions of said propeller-shaft hub are respectively journalled. a plurality of propeller blade bearings disposed on the sides' of said casand capable of restricted Y 3. A propeller apparatus, adapted to be mounted on the end of a propeller shaft, comprising a propeller-shaft hub,'a plurality of outstanding, irregularly contoured walls arranged on the outer surface of said hub, one of said walls lying in aplane substantially at a right angle to the axis of said shaft for a predetermined distance from one end of the wall, and merging into a spiral form as it advances to the opposite end, a twopart casing enclosing said propeller-shaft hub, bearings in the ends of said casing in which the outer end portions of the propeller-shaft hub are mounted for restricted rotation, a collar on each end of said casing securing the two parts together, a propeller blade rotatively mounted on the side of said casing in two or more circumferentially spaced positions thereon, and means interconnecting said propeller blades with the irregularly contoured walls so constructed and arranged that upon 'rotating said propeller-shaft hub in and with respect to said casing, said propeller blades are made to rotate on their axes.

4. A propeller apparatus for ship propulsion purposes comprising a plurality of axially unbalanced propeller blades, a pintle on each blade, a'two-part casing on the periphery of which a plurality of said blades are mounted for rotation on' their axes, a propeller-shaft hub member journalled in said casing and having a plurality of dssimilarly contoured grooves, said grooves being so formed that in changing the direction of rotation of the propeller from driving the ship astern 'to propelling it ahead, one of said blades starts rotating on its axis in advance of the remaining blades, a lug on each-blade, and

abutments on said casing, engaged by said lugs to limit axial rotation movements of the blades in each direction.

5. A. propeller adapted to be mounted on the end of a shaft for ship propulsion purposes, comprising a two-part casing, a bearing in each end of said casing, two propeller-blade bearings on opposite sides, respectively, of said casing, an axially unbalanced propeller blade mounted for axial rotation in each of the side bearings in.

said casing, a-.pintle on each of said propeller blades, a shaft hub member having two straight end portions iournalled, respectively, in the end bearings of said casing and an intermediate portion of spherical zone shape, two grooves, against the walls oi' which said pintles abut, cut on opposite sides, respectively, of the spherical zone portion of said hub member, one groove starting at the aft end of said portion and continuing therearound for a predetermined distance with slight lead, then spiralling gradually to the forward end of said portion, the other of the said grooves starting at its after end with a slight lead and interrupted by an abrupt projection which causes the engaging pintle to be swung on its orbit quickly to expedite the axial rotation of the blade to which it is attached, and bring this blade into transverse feathering position in advance of the movement of the other pintle which later causes the oppositely disposed blade to be rotated into a relatively similar angular position, both blades from these positions onwardly and until they arrive at their full pitch positions being axially rotated by impaction of their trailing portions on the water.

6. A propeller mechanism for ship propulsion comprising in combination with a propeller shaft a propeller-blade-carrying member, means for f mounting, for axial rotation, a plurality of propeller blades on said propeller-blade-carrying member, a grooved hub fixed on said shaft, said hub being disposed within, and having restricted rotary movement relative to, said propeller-bladecarrying member, and means associated with said propeller blades, co-acting with said grooved hub member, to rotate said blades on their axes, to the extent that the same cutting edges and driving faces are used in driving the ship either ahead or astern".

7. Al duplex, reversible-blade propeller comprising inl combination with a propeller shaft adapted to revolve in both directions, a shaft hub xed on said shaft, pintle-engaging means on the periphery of said shaft hub, a two-part casing in which said shaft hub is disposed and its ends journalled, two propeller-blade bearings positioned, respectively, on opposite sides of said casing, the faces of said bearings converging aftward, an axially unbalanced propeller blade, rotatable on its axis and having a hub' portion, mounted in each of the propeller-blade bearings, a pintle eccentrically positioned on the hub portion of each blade adapted, in co-action with said pintlecngaging means on the shaft hub, to rotate the blade when movement, relatively, between the shaft hub and the casing occurs, and means to limitthe rotary, axial movement of each blade in both directions.

MILTON D. THOMPSON. 

